Thoughts on: Using a 4afe ECU on a datsun a15

[jeremiahnz]

Hi guys,

I am looking at building a supercharged datsun a15. I would like to run this in an EFI setup, which is very rare factory for these engines (some A14's came with it). I also want to avoid the expense of aftermarket ECU's if possible, plus try something a bit different to see if it is possible.

The reason I am interested in using a 4afe ECU is because A) I have one and B) my brother had a 5afe successfully turbocharged by swapping the injectors and map sensor rather then changing the ECU which worked very well. This also works on a 7afe (1800cc) using the same map sensor and injectors. This seems to confirm that these ECU's can handle approx 15% fueling variation which is commonly reported. Therefore, if these ECU's were to receive inputs from their standard sensors I figure they could possibly be used on another vehicle. As I would be fabricating intakes, exhaust etc. there is no reason O2, temp sensors etc. from the toyota setup couldn't be used. Also a 4afe throttle body could be used so the ECU would receive all the tps signals.

I do however have some questions about some of the variations in the 4afe ECU specifically around ignition timing. Some older 4afes (from the ae101 series) had dizzy's rather then coil packs. In the ECU pinouts I have been able to find it shows inputs to the NE and G pins from crankshaft position sensors and camshaft angle sensors. Can anybody tell me if these are relevant to the older 4afe ECU's or whether they are for the new OBII and lean burn engines? Essentially my question is, do I have to provide a signal to the ECU for these pins and if so, how can I do it if I am using a non-Toyota distributor?

I'd be interested in other comments on how I may get this to work, or reasons it may not work.

Cheers

[ChaosAD]

The signals dont have to come from the crank and cam, they can usually both be from the dizzy mounted on the cam.

A lot of toyota's and other engines with nippon denso gear have a 24 tooth 'NE' wheel and 2 tooth 'g' wheel (or a 1 tooth g wheel and two pickups) in the dizzy or cas.

Just remember that if the wheel is on the cam it must have twice as many teeth as if it was on the crank as the cams spin at half crank speed.

Might want to check out this site, lot of good info there.
http://www.autoshop101.com/

For all the hasle why not just get a second hand link or megasquirt or something?

[NZ_AE86]

I see no problem with doing this, we've done similar things in the past with good results. If I was you I would adapt a toyota dizzy or CAS ot your Dato engine. The ecu will need these signals.

[soopachargen]

i know you already have the toyota gear, but have you thought about using say a honda or mitsi computer that can be chipped/reflashed so it can be tuned to suit the motor?

[jeremiahnz]

Thanks for the replies

NZ_AE86, what have you done similar to this? How would you go about adapting a toyota dizzy to the datto engine? Would it just be a case of keeping the drive gear from the datto dizzy and try to fit the top part of the toyota dizzy to it?

ChaosAD, thanks for the detail. I will read up a bit more on the Ne and G signals. I may still end up using an aftermarket computer - this just seemed like an interesting challenge.